Utilization of Fisheries' By-Products for Functional Foods
Se-Kwon Kim in Marine Biochemistry, 2023
Chitin and chitosan are natural polymers that are well known as mucopolysaccharide, which is abundant in the shell wall of marine invertebrates (Ganesan et al., 2020). Chitin is the most abundant and widely distributed amino polysaccharide polymer found in nature. Chitin performs as the building material that gives strength to the exoskeletons of crustaceans, insects, and the cell walls of fungi (Azuma and Ifuku, 2016; Elieh-Ali-Komi and Hamblin, 2016; Philibert et al., 2017). Chitin is a poly-β- [1, 4]-N-acetyl-d-glucosamine or poly (N-acetyl D-glucosamine). Due to the solid hydrogen bonding between the amide groups and the carbonyl groups of the nearby chains, chitin occurs in three polymorphic forms: α-, β-, and γ- (Philibert et al., 2017). Chitosan (poly β-(1–4)-D-glucosamine) is a cationic linear polysaccharide obtained by partial deacetylation of chitin. It is composed of randomly distributed β-(1–4)-linked D-glucosamine (deacetylated unit) and N-acetyl-D-glucosamine (acetylated unit; Dima et al., 2017).
Marine-Based Carbohydrates as a Valuable Resource for Nutraceuticals and Biotechnological Application
Se-Kwon Kim in Marine Biochemistry, 2023
Seafood such as crabs, shrimps, lobsters, and oysters are rich in protein content and thus consumed every year to gain protein. However, half of the body mass is represented by non-edible parts and external shells of crustaceans that are usually considered as waste and discarded. Coastal waste and shrimp industries generate a large amount of biowaste that can be transformed to value-added products as chitosan (Hamed et al., 2016). Chitin is used as a raw material for the production of chitosan. Crustacean shells have a rich chemical composition of 30% to 50% of calcium carbonate/phosphate, 20% to 30% of chitin, and 30% to 40% of protein that attracts people’s attention towards chitin extraction (Kumari et al., 2015). The process of converting chitin to chitosan causes a good change, lowering the molecular weight and altering the distribution of charge and DDA that influence several applications (Younes and Rinaudo, 2015). Extraction of chitin involves two methods: chemical and biological methods. Both methods involve deacetylation for the formation of chitosan from chitin. But chemical deacetylation is more preferred for the industrial production of chitosan because of the low cost and utility of mass production (Cheung et al., 2015).
Comparative Immunology
Julius P. Kreier in Infection, Resistance, and Immunity, 2022
Invertebrates protect themselves against invasion by processes of phagocytosis, humoral immunity, and cell-mediated immunity as well as by physical barriers. For example, arthropods have tough exoskeletons made of chitin that can protect them against all types of attackers. The horseshoe crab (Limulus polyphemus) not only has a hard exoskeleton but can also protect itself against bacterial endotoxins by secreting a specialized glycoprotein through pores in the carapace. On contact with bacterial endotoxins, this glycoprotein coagulates, sealing the pores and immobilizing any invading bacteria. Other invertebrates such as the coelenterates, annelids, mollusca, and echinoderms may secrete masses of sticky antibacterial mucus when attacked thereby immobilizing potential invaders.
Impact of the functional coating of silver nanoparticles on their in vivo performance and biosafety
Published in Drug Development and Industrial Pharmacy, 2023
Hesham M. Tawfeek, Mahmoud A. Younis, Basmah Nasser Aldosari, Alanood Sunhat Almurshedi, Ahmed Abdelfattah, Jelan A. Abdel-Aleem
Functional coating of inorganic nanoparticles is a promising strategy to modulate their in vivo performance, biodistribution, clearance, and biosafety. A wide variety of biopolymers were investigated as functional coatings such as poly(ethylene glycol) (PEG), cellulose, sodium alginate, and poly(vinyl pyrrolidone) (PVP) [9,11–13]. Furthermore, the functional coating can be a more clinically-translatable approach in terms of scalability in comparison with the classic ligand-based targeting. Chitosan (CHI) is a carbohydrate-based polymer of N-acetyl-D-glucosamine, synthesized via the deacetylation of the naturally-occurring polymer, chitin. Thanks to its attractive features including ease of synthesis, ease of chemical modification, flexibility, and high tolerability, CHI has been investigated in a wide diversity of drug delivery applications [14]. Moreover, the biodegradability of chitosan has prompted its use as a biosafe polymeric coating in several drug delivery platforms [15]. Furthermore, numerous recent studies revealed some interesting biological activities of CHI including hypocholesterolemic, antimicrobial, immunostimulant, antioxidant, anti-inflammatory, and anticancer effects [16–18].
Scylla Sp. Shell: a potential green adsorbent for wastewater treatment
Published in Toxin Reviews, 2022
Azrul Nurfaiz Mohd Faizal, Nicky Rahmana Putra, Muhammad Abbas Ahmad Zaini
Chitin (C8H13O5N)n is the second most abundant biopolymer on earth. A linear poly-β-(1, 4)-N-acetyl-D-glucosamine cellulose-like polysaccharide is tasteless, odorless, yellowish/white in color, and highly hydrophobic (Anastopoulos et al.2017). It is composed of three polymorphic forms, i.e., α-chitin (anti-parallel strands), β-chitin (parallel chains), and γ-chitin (combination of α and β structures) (Khoushab and Yamabhai 2010). Among others, α-chitin bears an 80% crystallinity index is the most stable because the anti-parallel orientation of polysaccharide gives the maximum bonds in chitin fiber (Begum et al.2021). Chitin can be converted into chitosan via deacetylation. Chitosan contains copolymers of N-acetyl-D-glucosamine (acetylated units) and D-glucosamine (deacetylated units) linked by β(1,4)-glycosidic bonds (Begum et al.2021).
Alantolactone modulates the production of quorum sensing mediated virulence factors and biofilm formation in Pseudomonas aeruginosa
Published in Biofouling, 2022
V T Anju, Siddhardha Busi, Sandeep Kumar, Kitlangki Suchiang, Ranjith Kumavath, Sampathkumar Ranganathan, Dinakara Rao Ampasala, Madhu Dyavaiah
LasA protease can lyse heat boiled Staphylococcus aureus. Around 30 ml of 24 h grown S. aureus culture was boiled for 10 min, and the cell pellet was collected after centrifugation. The cell pellet was dissolved in Na2PO4 buffer (10 mM), and density was maintained to 0.5 McFarland at OD600. The treated and untreated culture supernatants were mixed with boiled S. aureus cells in 1:9 ratio, and the decrease in turbidity was recorded at 600 nm at regular time intervals (0, 5, 10, 20, 30, 40, 50 and 60 min) (Anju et al. 2021). Alkaline protease activity was quantified by following a method with slight modification as described by González-Olvera et al. (2019). To measure alkaline protease activity, 25 mg of Hide Remazol Brilliant Blue R (500 μl) was mixed with buffer (pH 8.0, 20 Mm Tris-HCl and 1 mM CaCl2) and added to 170 μl of supernatant. The mixture was incubated at 37 °C for 1 h, and the alkaline protease activity was measured at 590 nm (González-Olvera et al. 2019). Chitin azure was employed as a substrate for analyzing the chitinase activity of phytochemicals. Chitinase is important for the test bacteria to aid in the initial biofilm formation and adhesion to host epithelial cells for establishing pathogenesis (Tran et al. 2011). The substrate (0.5 mg ml−1) was dissolved in 0.1 M sodium citrate buffer of pH 4.8 and supplemented with the culture supernatant (1:2 ratio). The reaction mixture was preserved for 7 days at 37 °C with continuous agitation. The activity was measured at 570 nm after 7 days (Husain et al. 2017).